The project's long-term objective is to develop an enhanced, computerized health risk appraisal, the All-Cause Mortality Risk Profile (ACMRP), incorporating an objective measure of physical fitness, the maximal graded treadmill stress test, into mortality risk factors. More that 17,000 patients with over 140,000 person-years of follow-up in the on- going Aerobics Center Longitudinal Study (ACLS) have been analyzed for morbidity and mortality through 1985. Approximately 95% of these patients have been traced and vital status determined, with 483 and 575 deaths coded for cause of death. Initial analyses suggest that individuals in the bottom 20% on physical fitness at their initial clinic visit have over 1.5 times the risk of death from any cause when compared to the most fit patients. This increased risk was observed even after controlling for the effects of other important risk factors, including cholesterol, age, BMI, resting blood pressure, exercise habits, and smoking habits, These results suggest that low physical fitness is a powerful risk factor for total mortality. The inclusion of an objective measure of physical fitness in the ACMRP will provide a more inclusive, innovative, and commercial risk profile for clinical and wellness environments.